blob: d7c6a24378cf50e1c0ef720b94fa4b67db9d010a [file] [log] [blame]
* Copyright (c) 2016, Alliance for Open Media. All rights reserved
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at
#include "config/aom_dsp_rtcd.h"
#include "config/av1_rtcd.h"
#include "av1/common/filter.h"
#include "av1/common/scale.h"
#include "aom_dsp/aom_filter.h"
static int get_fixed_point_scale_factor(int other_size, int this_size) {
// Calculate scaling factor once for each reference frame
// and use fixed point scaling factors in decoding and encoding routines.
// Hardware implementations can calculate scale factor in device driver
// and use multiplication and shifting on hardware instead of division.
return ((other_size << REF_SCALE_SHIFT) + this_size / 2) / this_size;
// Given the fixed point scale, calculate coarse point scale.
static int fixed_point_scale_to_coarse_point_scale(int scale_fp) {
// Note: x and y are integer precision, mvq4 is q4 precision.
MV32 av1_scale_mv(const MV *mvq4, int x, int y,
const struct scale_factors *sf) {
const int x_off_q4 = av1_scaled_x(x << SUBPEL_BITS, sf);
const int y_off_q4 = av1_scaled_y(y << SUBPEL_BITS, sf);
const MV32 res = {
av1_scaled_y((y << SUBPEL_BITS) + mvq4->row, sf) - y_off_q4,
av1_scaled_x((x << SUBPEL_BITS) + mvq4->col, sf) - x_off_q4
return res;
void av1_setup_scale_factors_for_frame(struct scale_factors *sf, int other_w,
int other_h, int this_w, int this_h) {
if (!valid_ref_frame_size(other_w, other_h, this_w, this_h)) {
sf->x_scale_fp = REF_INVALID_SCALE;
sf->y_scale_fp = REF_INVALID_SCALE;
sf->x_scale_fp = get_fixed_point_scale_factor(other_w, this_w);
sf->y_scale_fp = get_fixed_point_scale_factor(other_h, this_h);
sf->x_step_q4 = fixed_point_scale_to_coarse_point_scale(sf->x_scale_fp);
sf->y_step_q4 = fixed_point_scale_to_coarse_point_scale(sf->y_scale_fp);